Journal of Liquid Chromatography, 5(12), 2293-2309 (1982) the Effect of Silanol Masking on the Recovery of Picloram and Other Solutes from a Hydrocarbonaceous Pre-analysis Extraction Column

The recoveries of picloram, picloram-methylester, hexazinone, benzene, and acetophenone from aqueous samples were studied using a commercially available hydrocarbonaceous pre—analysis extraction cartridge, both with and without tetrabutylammonium hydrogen sulfate (TBAHS) in the eluent. Extraction efficiency was found to be dependent on sample loading volume. The results suggest a mixed mechanism of retention involving both "silanophilic" and "hydrophobic" interactions in the absence of tetrabutylammonium ion. The ability of TBAHS to mask surface silanol groups and/or ion—pair with counterionic solutes is invoked to explain the observations. Chromatograms of the solutes obtained on a C^g bonded analytical column in both the presence and absence of TBAHS are also presented.